In a typical digital camera, an image beam is directed through a lens and onto an imager or image sensor, for example a CCD (Charge Coupled Device), comprised of an array of sensing elements. The lens and the CCD need to be properly positioned relative to each other within the digital camera to provide a focused image. In order to properly position the CCD, the position of the CCD needs to be determined. Such a position can be determined relative to a reference surface or reference plane on the digital camera.
U.S. Pat. Nos. 5,757,485 (Marcus et al) and 5,757,486 (Marcus et al), commonly assigned and incorporated herein by reference, relate to a digital camera image sensor positioning apparatus and method which includes a non-coherent light interferometer. The apparatus and method include an optical probe assembly removably mountable to a digital camera. The non-coherent light interferometer is in communication with the optical probe assembly to determine a depth from a reference surface to the image surface and optical probe assembly. The apparatus and method have been suitable for their intended purpose, however, a need continues to exist for an apparatus and method for calibrating the optical probe assembly. Such an apparatus and method should be robust, comprise simple assembly, be readily constructed and aligned, and usable in a manufacturing environment, particularly by novice users.